detonation/pre ignition

[paul24685]

hi i recently changed my thermostat as the car was sitting a bit hotter than i would have liked it never had went into red but used to regularly hit100c as thats when stat opened. anyway when it was running after say 30 mins when i feather the gas pedal you could hear a rattle noise seemed worse when i put 95 octane in when i changed stat i xpected it to stop as i put it down to heat build up in cylinder. but its still doing it not as bad as it was but i want to stop it completly im thinking changing spark plugs could do it:) and i did hear somewhere it could be air and fuel mixture is off is it just as simple as disconcting battery overnight to reset ecu? appreciate any help guys once i get this sorted il be very happy with the car lol.thanks for reading.

[paul24685]

meant to say also it only happens when am moving i thought it was exhaust heat sheild as am missing a bolt on it but as i ssaid it seems to get worse with low octane fuel thats why im thinking detonation. thanks again dudes;)

[jordyp]

check your spark plugs mate? also is there enough oil and water in your engine? check your oil if its black then change oil, where about is the noise coming from and what kind of noise?

[paul24685]

cheers jordy its like mettalic rattle type noise as soon as i put my foot down a bit more you dont hear it just seems to be when i feather gas to keep my speed up also very hard to tell where its coming from as it only happens when on the move. coolant and oil is spot on as well.

[jordyp]

trying to think. not really came around something like that. my car is making a noise the now can only hear when idiling but thats aux belt

[paul24685]

only thing i can think of is when iv been running it a few degrees hotter than normal maybe the spark plugs have got damaged will check em tommorow and post up what they are like.

[jordyp]

the noise wont be the spark plugs i dont think

[paul24685]

checked my plugs today seemed spot on to me. car did lots of short journeys before i got it only other two things i can think of is timing slightly out which if it is id imagine i would get the rattle all time??? or i have carbon build up but i was thinking the plugs would have black sooty bits on em if that was the case or am i wrong??? im stumped:/